1. Field of the Invention
The present invention relates to a display module, and in particular relates to a display module in which electrostatic discharge is electrically grounded from the light emitting surface of a display panel.
2. Description of the Related Art
With the advancement in technology, liquid crystal displays (LCD) have been widely applied in various electronic products such as TVs, computer screens, notebook computers, mobile phones and personal digital assistants (PDA).
Electrostatic charges are generated during the LCD panel manufacturing process, such as during LCD panel edge cutting, rubbing, or moving, and enter the LCD panel via the wires extended to the edge of the LCD panel and damage the LCD panel. The LCD panel is more likely to be damaged during fabrication. In some cases, the LCD panel is discarded which results in lower yield rates of the LCD panel. Thus, an electrostatic discharge (ESD) protection mechanism has been disclosed.
For the typical LCD panel (such as TN mode, VA mode, etc.), a conductive electrode is formed at a TFT array substrate and CF substrate, and the electrostatic discharge produced therefrom can be discharged via the conductive electrode. Thus, the charge accumulated in the LCD is discharged. On the contrary, for an in-plane switching (IPS) LCD panel, there is no conductive electrode formed at the CF substrate; therefore, the potential risk from ESD damage is increased due the accumulation of charges therein. To solve this problem, a light transmissive electrode is coated on an outer side of the CF substrate of the typical IPS LCD panel, which is opposite to the side where the LC layer is connected thereto as an ESD protection mechanism.
Please refer to FIG. 1, which shows a conventional display module 1. In the display module 1, the electrostatic discharge from a display panel 11 is guided to a front bezel 13 by a conductive material 12 which is sandwiched between the display panel 11 and the front bezel 13. In order to ensure the conductive material 12 is in contact with the display panel 11 firmly, a pressure is applied by the front bezel 13 in an inward direction. However, a pinch mura defect occurs because the pressure causes rotation of the liquid molecular in the display panel 11. Moreover, misalignment of the conductive material 12 may also occur resulting in the electrostatic discharge not being able to be released.
Please refer to FIG. 2, which shows a conventional display module 2. In the display module 2, the electrostatic discharge from a display panel 21 is guided to a rear bezel 23 by a conductive tape 22 which is connected between the display panel 21 and the rear bezel 23. However, the conductive tape 22 is easily peeled off from the display panel 21, as shown by the dotted line, by an external force produced by mechanical shock while moving the display module 2. Meanwhile, it is difficult to precisely attach the conductive tape 22 to a predetermined position between the display panel 21 and the rear bezel 23 due to the lack of roughness of the conductive tape 22. Also, because the conductive tape 22 may be less sticky while being used in a humid and high temperature environment, after a long time of use in the display module 2, the conductive tape 22 may drop therefrom.